/*      $NetBSD: nfs_clnode.c,v 1.3 2016/12/13 22:17:33 pgoyette Exp $  */
/*-
 * Copyright (c) 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Rick Macklem at The University of Guelph.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      from nfs_node.c 8.6 (Berkeley) 5/22/95
 */

#include <sys/cdefs.h>
/* __FBSDID("FreeBSD: head/sys/fs/nfsclient/nfs_clnode.c 302210 2016-06-26 14:18:28Z kib "); */
__RCSID("$NetBSD: nfs_clnode.c,v 1.3 2016/12/13 22:17:33 pgoyette Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/fcntl.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/taskqueue.h>
#include <sys/vnode.h>

#include <vm/uma.h>

#include <fs/nfs/common/nfsport.h>
#include <fs/nfs/client/nfsnode.h>
#include <fs/nfs/client/nfsmount.h>
#include <fs/nfs/client/nfs.h>
#include <fs/nfs/client/nfs_kdtrace.h>

#include <fs/nfs/common/nfs_lock.h>

extern struct vop_vector newnfs_vnodeops;
extern struct buf_ops buf_ops_newnfs;
MALLOC_DECLARE(M_NEWNFSREQ);

uma_zone_t newnfsnode_zone;

const char nfs_vnode_tag[] = "nfs";

static void     nfs_freesillyrename(void *arg);

void
ncl_nhinit(void)
{

        newnfsnode_zone = uma_zcreate("NCLNODE", sizeof(struct nfsnode), NULL,
            NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
}

void
ncl_nhuninit(void)
{
        uma_zdestroy(newnfsnode_zone);
}

/*
 * ONLY USED FOR THE ROOT DIRECTORY. nfscl_nget() does the rest. If this
 * function is going to be used to get Regular Files, code must be added
 * to fill in the "struct nfsv4node".
 * Look up a vnode/nfsnode by file handle.
 * Callers must check for mount points!!
 * In all cases, a pointer to a
 * nfsnode structure is returned.
 */
int
ncl_nget(struct mount *mntp, u_int8_t *fhp, int fhsize, struct nfsnode **npp,
    int lkflags)
{
        struct thread *td = curthread;  /* XXX */
        struct nfsnode *np;
        struct vnode *vp;
        struct vnode *nvp;
        int error;
        u_int hash;
        struct nfsmount *nmp;
        struct nfsfh *nfhp;

        nmp = VFSTONFS(mntp);
        *npp = NULL;

        hash = fnv_32_buf(fhp, fhsize, FNV1_32_INIT);

        MALLOC(nfhp, struct nfsfh *, sizeof (struct nfsfh) + fhsize,
            M_NFSFH, M_WAITOK);
        bcopy(fhp, &nfhp->nfh_fh[0], fhsize);
        nfhp->nfh_len = fhsize;
        error = vfs_hash_get(mntp, hash, lkflags,
            td, &nvp, newnfs_vncmpf, nfhp);
        FREE(nfhp, M_NFSFH);
        if (error)
                return (error);
        if (nvp != NULL) {
                *npp = VTONFS(nvp);
                return (0);
        }
        np = uma_zalloc(newnfsnode_zone, M_WAITOK | M_ZERO);

        error = getnewvnode(nfs_vnode_tag, mntp, &newnfs_vnodeops, &nvp);
        if (error) {
                uma_zfree(newnfsnode_zone, np);
                return (error);
        }
        vp = nvp;
        KASSERT(vp->v_bufobj.bo_bsize != 0, ("ncl_nget: bo_bsize == 0"));
        vp->v_bufobj.bo_ops = &buf_ops_newnfs;
        vp->v_data = np;
        np->n_vnode = vp;
        /* 
         * Initialize the mutex even if the vnode is going to be a loser.
         * This simplifies the logic in reclaim, which can then unconditionally
         * destroy the mutex (in the case of the loser, or if hash_insert
         * happened to return an error no special casing is needed).
         */
        mtx_init(&np->n_mtx, "NEWNFSnode lock", NULL, MTX_DEF | MTX_DUPOK);
        /*
         * NFS supports recursive and shared locking.
         */
        lockmgr(vp->v_vnlock, LK_EXCLUSIVE | LK_NOWITNESS, NULL);
        VN_LOCK_AREC(vp);
        VN_LOCK_ASHARE(vp);
        /* 
         * Are we getting the root? If so, make sure the vnode flags
         * are correct 
         */
        if ((fhsize == nmp->nm_fhsize) &&
            !bcmp(fhp, nmp->nm_fh, fhsize)) {
                if (vp->v_type == VNON)
                        vp->v_type = VDIR;
                vp->v_vflag |= VV_ROOT;
        }
        
        MALLOC(np->n_fhp, struct nfsfh *, sizeof (struct nfsfh) + fhsize,
            M_NFSFH, M_WAITOK);
        bcopy(fhp, np->n_fhp->nfh_fh, fhsize);
        np->n_fhp->nfh_len = fhsize;
        error = insmntque(vp, mntp);
        if (error != 0) {
                *npp = NULL;
                FREE((caddr_t)np->n_fhp, M_NFSFH);
                mtx_destroy(&np->n_mtx);
                uma_zfree(newnfsnode_zone, np);
                return (error);
        }
        error = vfs_hash_insert(vp, hash, lkflags, 
            td, &nvp, newnfs_vncmpf, np->n_fhp);
        if (error)
                return (error);
        if (nvp != NULL) {
                *npp = VTONFS(nvp);
                /* vfs_hash_insert() vput()'s the losing vnode */
                return (0);
        }
        *npp = np;

        return (0);
}

/*
 * Do the vrele(sp->s_dvp) as a separate task in order to avoid a
 * deadlock because of a LOR when vrele() locks the directory vnode.
 */
static void
nfs_freesillyrename(void *arg)
{
        struct sillyrename *sp;

        sp = arg;
        vrele(sp->s_dvp);
        free(sp, M_NEWNFSREQ);
}

static void
ncl_releasesillyrename(struct vnode *vp, struct thread *td)
{
        struct nfsnode *np;
        struct sillyrename *sp;

        ASSERT_VOP_ELOCKED(vp, "releasesillyrename");
        np = VTONFS(vp);
        mtx_assert(&np->n_mtx, MA_OWNED);
        if (vp->v_type != VDIR) {
                sp = np->n_sillyrename;
                np->n_sillyrename = NULL;
        } else
                sp = NULL;
        if (sp != NULL) {
                mtx_unlock(&np->n_mtx);
                (void) ncl_vinvalbuf(vp, 0, td, 1);
                /*
                 * Remove the silly file that was rename'd earlier
                 */
                ncl_removeit(sp, vp);
                crfree(sp->s_cred);
                sysmon_task_queue_sched(0, nfs_freesillyrename, sp);
                mtx_lock(&np->n_mtx);
        }
}

int
ncl_inactive(struct vop_inactive_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct nfsnode *np;
        boolean_t retv;

        if (NFS_ISV4(vp) && vp->v_type == VREG) {
                /*
                 * Since mmap()'d files do I/O after VOP_CLOSE(), the NFSv4
                 * Close operations are delayed until now. Any dirty
                 * buffers/pages must be flushed before the close, so that the
                 * stateid is available for the writes.
                 */
                if (vp->v_object != NULL) {
                        VM_OBJECT_WLOCK(vp->v_object);
                        retv = vm_object_page_clean(vp->v_object, 0, 0,
                            OBJPC_SYNC);
                        VM_OBJECT_WUNLOCK(vp->v_object);
                } else
                        retv = TRUE;
                if (retv == TRUE) {
                        (void)ncl_flush(vp, MNT_WAIT, NULL, ap->a_td, 1, 0);
                        (void)nfsrpc_close(vp, 1, ap->a_td);
                }
        }

        np = VTONFS(vp);
        mtx_lock(&np->n_mtx);
        ncl_releasesillyrename(vp, ap->a_td);

        /*
         * NMODIFIED means that there might be dirty/stale buffers
         * associated with the NFS vnode.  None of the other flags are
         * meaningful after the vnode is unused.
         */
        np->n_flag &= NMODIFIED;
        mtx_unlock(&np->n_mtx);
        return (0);
}

/*
 * Reclaim an nfsnode so that it can be used for other purposes.
 */
int
ncl_reclaim(struct vop_reclaim_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct nfsnode *np = VTONFS(vp);
        struct nfsdmap *dp, *dp2;

        /*
         * If the NLM is running, give it a chance to abort pending
         * locks.
         */
        if (nfs_reclaim_p != NULL)
                nfs_reclaim_p(ap);

        mtx_lock(&np->n_mtx);
        ncl_releasesillyrename(vp, ap->a_td);
        mtx_unlock(&np->n_mtx);

        /*
         * Destroy the vm object and flush associated pages.
         */
        vnode_destroy_vobject(vp);

        if (NFS_ISV4(vp) && vp->v_type == VREG)
                /*
                 * We can now safely close any remaining NFSv4 Opens for
                 * this file. Most opens will have already been closed by
                 * ncl_inactive(), but there are cases where it is not
                 * called, so we need to do it again here.
                 */
                (void) nfsrpc_close(vp, 1, ap->a_td);

        vfs_hash_remove(vp);

        /*
         * Call nfscl_reclaimnode() to save attributes in the delegation,
         * as required.
         */
        if (vp->v_type == VREG)
                nfscl_reclaimnode(vp);

        /*
         * Free up any directory cookie structures and
         * large file handle structures that might be associated with
         * this nfs node.
         */
        if (vp->v_type == VDIR) {
                dp = LIST_FIRST(&np->n_cookies);
                while (dp) {
                        dp2 = dp;
                        dp = LIST_NEXT(dp, ndm_list);
                        FREE((caddr_t)dp2, M_NFSDIROFF);
                }
        }
        if (np->n_writecred != NULL)
                crfree(np->n_writecred);
        FREE((caddr_t)np->n_fhp, M_NFSFH);
        if (np->n_v4 != NULL)
                FREE((caddr_t)np->n_v4, M_NFSV4NODE);
        mtx_destroy(&np->n_mtx);
        uma_zfree(newnfsnode_zone, vp->v_data);
        vp->v_data = NULL;
        return (0);
}

/*
 * Invalidate both the access and attribute caches for this vnode.
 */
void
ncl_invalcaches(struct vnode *vp)
{
        struct nfsnode *np = VTONFS(vp);
        int i;

        mtx_lock(&np->n_mtx);
        for (i = 0; i < NFS_ACCESSCACHESIZE; i++)
                np->n_accesscache[i].stamp = 0;
        KDTRACE_NFS_ACCESSCACHE_FLUSH_DONE(vp);
        np->n_attrstamp = 0;
        KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
        mtx_unlock(&np->n_mtx);
}